The efforts controlling scattering losses have been effective in the structure known as a superlattice, made up of a line of thin epitaxial regions of semiconductors with different properties, wherein the width dimension of regions in the superlattice is reduced to less than the electron mean free path and the carrier transport in certain directions is restricted.
As the art has developed, a variety of engineered structures have exhibited extraordinary transport and optical properties. A goal in semiconductor superlattices is to produce a structure in which the dimensionality of carrier movement is reduced.
The development of the superlattice art and a description of the goals that the superlattices are to achieve is described in "Semiconductor Superlattices and Quantum Wells" by Leo Esaki published in the Proceedings of the 17th International Conference on the Physics of Semiconductors, San Francisco, Calif., Aug. 6-10, 1984, beginning on page 473.
There have been two structures in the art in which an effort has been made to use a superlattice to provide single dimensional carrier movement. Both structures use an inversion layer adjacent an interface for confinement in one direction and a superlattice region thickness for confinement in a second direction leaving freedom of carrier movement in the third direction. The first is in the Japanese Journal of Applied Physics, Vol. 19, No. 12, December 1980, pp. L735-L738 wherein, a V shaped structure gate in a GaAs/GaAlAs superlattice produces an inversion layer in an intermediate region of the superlattice adjacent the gate. The second is in the IBM Technical Disclosure Bulletin Vol. 27, No. 4B, September 1984, p. 2592 in which an inversion layer adjacent an interface across a plurality of superlattice regions provides oscillator performance.